As you may know, Apple released FaceTime with downside of it only working when connected to a WiFi network. While there have been numerous ways to enable this feature through hacks and packages on Cydia, code was recently found that would enable this with a simple change in iFile. Check out the steps below and get started.

To enable FaceTime over 3G a file within the iPhone's system needs to be edited. This can be done for free via SSH or by using a program right on your iPhone called iFile. iFile will allow you to complete the whole process on your iPhone, the only downside being it costs $4 at this time. iFile can be downloaded by searching Cydia and purchasing. A computer is required to utilize the free SSH method and will be explained below. Be sure your iPhone 4 is jailbroken. If you need help jailbreaking, check out this tutorial. Jailbreak at your own risk.

Step By Step

Step 1. The first steps of this knit will be focused on the SSH method. If you plan on using iFile to complete this process on the iPhone itself, skip on down to Step 7.

Step 2. Download and install Cyberduck on either your Mac or PC.

Step 3. You'll need to install OpenSSH on your iPhone via Cydia. This can be done by simply opening Cydia and searching for Open SSH.

Step 4. Once you've completed the above steps, launch Cyberduck and click Open Connection. Select SFTP from the drop down menu. In the server field you'll put your iPhone's IP adress. This can be found by going to the Settings app, clicking on WiFi, and clicking the blue arrow beside the network name you are connected to. You'll see the IP adress of your iPhone. Insert that into the Server field.

Step 5. In the Username field you'll type root and in the Password field you'll type alpine.

Step 6. Click Connect and you'll be inside your iPhone's file system. The first connection may take a few minutes, so be patient.

Step 7. Using your choice of file editing methods listed above, Cyberduck or iFile, navigate to /System/Library/CoreServices/SpringBoard.app/.

Step 3. Find the file called N90AP.plist and open it to edit.

Step 4. You'll want to add the following code below as shown in the pictures below.

<key>3Gvenice</key>
<true/>

Step 5. After editing this file you should be able to operate FaceTime over WiFi or 3G by default.

That's it. Super easy, and super convenient for those times when you need a quick video chat but aren't at home.